1. Field of the Invention
The present invention relates to a processing apparatus, and more particularly, to a sputtering apparatus capable of easily processing a large-area substrate, a method of driving the sputtering apparatus, and a method of manufacturing a substrate using the sputtering apparatus.
2. Discussion of the Related Art
A substrate, such as a semiconductor wafer or a display panel (such as a liquid crystal display (LCD) device or a plasma display panel (PDP)), is manufactured by repeatedly performing a plurality of processes such as deposition and etching. Each process uses a separate processing apparatus. Among the apparatuses, there are sputtering apparatuses for deposition.
FIG. 1 illustrates a sectional view of a sputtering apparatus according to the related art.
Referring to FIG. 1, the sputtering apparatus includes a susceptor 2 having a substrate securely seated thereon and a plurality of target devices 4. The target devices 4 face the susceptor 2 or the substrate 1 and are arranged in a line on the same surface. Each target device 4 includes a target 5, a baking plate 6 and a magnet 7. The target 5 emits target particles and is fixed on the front surface of the baking plate 6 that faces the susceptor 2. The baking plate 6 supports the target 5 and maintains the temperature of the target 5 to a constant room temperature. The magnet 7 on the rear surface of the baking plate 6 allows electrons to collect to facilitate a plasma discharge in an internal space 8 between the target 5 and the susceptor 2.
The following describes an operation of the above sputtering apparatus. An inert gas, such as Ar gas, fills the internal space 8 between the target 5 and the susceptor 2. When a predetermined positive voltage is supplied to the susceptor 2 and a predetermined negative voltage is supplied to the target 5, Ar gas is ionized to Ar+ ions to generate plasma. Because more electrons are collected by the magnetic field of the magnet 7, the generated plasma becomes high-density plasma. A region of the high-density plasma contains Ar+ ions. A predetermined potential difference occurs between the region of the high-density plasma and the target 5. The Ar+ ions contained in the high-density plasma region are accelerated by the energy of the predetermined potential difference and thus collide against the target 5. These collisions cause the target 5 to emit target particles, and the emitted target particles are deposited on the substrate 1.
With a recent increase in the size of a substrate to be processed, the requirements on a sputtering apparatus for processing such a substrate have also increased.
In particular, the number of the target devices 4 needed increases with increased substrate size, thereby increasing the cost and size of the sputtering apparatus. In the related art, the width “w2” of a gap between adjacent target devices 4 is controlled to be very small (the width “w2” being much smaller than the width “w1” of the target device 4) so that target particles substantially uniformly deposit on the substrate 1, thereby requiring a large number of target devices. In addition, in order to substantially uniformly deposit target particles on an edge region of the substrate 1, target devices 4 are provided such that the total width “d2” of the target devices 4 is greater than the width “d1” of the substrate 1. Accordingly, the size of the sputtering apparatus further increases and thus the occupation area of the sputtering apparatus further increases.
Further, target devices 4 are securely fixed to an external wall or a support such that the target devices 4 cannot shift or rotate in any direction (e.g., a vertical direction or a horizontal direction). Accordingly, target particles emitted from each target 5 are deposited mainly on the portion of the substrate 1 opposite to each target 5. That is, as shown in FIG. 2, Ar+ ions located in front of the target 5 collide with the target, and target particles are emitted from the target 5 by the above collision. The emitted target particles are slightly spread and deposited on the facing substrate 1. At a boundary region between adjacent targets, emitted target particles are deposited on the substrate 1 from both of the adjacent targets. Accordingly, as shown in FIG. 3, more target particles are deposited on a first region p1 of the substrate 1, which is opposite to the boundary region between the adjacent targets 5, than on a second region p2 of the substrate 1, which is opposite to the target 5. Consequently, a layer 9 formed on the substrate 1 has an uneven surface.
The substrate 1 having the uneven layer 9 formed thereon, may be poor in terms of operation characteristics and image-quality characteristics.